Thinking, Fast and Slow — heuristics, fluency, and dual-process judgment

Daniel Kahneman · 1/38 ch.

Thinking, Fast and Slow

Human judgment runs through fast heuristics and slower deliberation; many errors come from treating intuitive fluency as reliable reasoning.

mechanism · Thinking, Fast and Slow

Fast cognition optimizes for coherent stories before careful accuracy checks

Fast judgment produces an immediately usable interpretation by assembling a plausible story from partial cues.

“Paraphrase: quick thought builds the most coherent account it can from the evidence at hand.”

Speed comes from compressing evidence into a coherent narrative early, while slower checking happens later if it happens at all.

Rough Synthesis · Distilling

System 1 quickly produces coherent judgments from sparse evidence

The fast mind is optimized for immediate coherence, not careful audit. It fills gaps quickly and treats the resulting story as if it were well-grounded.

“Paraphrase: fast cognition tends to build the most coherent story it can from limited cues.”

This explains why confident first impressions can dominate later reasoning.